The present invention relates to a process cartridge which has a component carrying out image formation and a nonvolatile memory storing prescribed information corresponding to addresses and is detachably attached to a main body of an image forming device.
In recent years, primarily for the purpose of recycling of resources, a process cartridge detachably attached to a main body of an image forming device is being widely used. Process cartridges of this kind include the one integrally including a photoreceptor drum, charger, exposing device, developing device, cleaner and toner reservoir required to perform a known electrophotography process as well as a nonvolatile memory storing information about the process cartridge.
Characteristics of the process cartridge of this kind are tuned according to the climate or the like in a shipment destination district. In the nonvolatile memory, destination data indicating the shipment destination district such as the domestic market, the North American market or the like is stored. Consequently, when the process cartridge is attached to the main body of the image forming device, a control system of the main body of the image forming device reads the destination data stored in the nonvolatile memory of the process cartridge before printing operation so as to confirm whether the shipment destination district of the process cartridge matches the shipment destination district of the main body of the image forming device. Therefore, only a process cartridge matching the main body of the image forming device can be used and thus an appropriate printing operation can be performed.
For example, when a “standard pack”, which is a pack containing one process cartridge when shipped, and a “value pack”, which is a pack containing a plurality of process cartridges when shipped, are compared, the process cartridges in the respective packs are the same, but the required number, type and the like of pack material are different. Therefore, these packs need separate destination codes for a reason of production management, particularly, from the viewpoint of payment slip processing. For example, it is assumed that only the “standard pack” is sold in the domestic market for an initial period after release of the product and that destination data stored in the nonvolatile memory of the process cartridge is only “123”, which indicates that the destination is the domestic market. After a while, when the “value pack” is released in the domestic market in response to a demand from the market, separate destination data, for example, “124”, needs to be stored in the nonvolatile memory of the process cartridge even though the shipment destination districts are the same.
However, since only one kind of destination data is stored in a conventional process cartridge, the main body of the image forming device for the domestic market (programmed to use only process cartridges whose destination data is “123”) does not accept those whose destination data is “124” unless a change is made. In order to use a process cartridge of the “value pack”, a program (software) of the main body of the image forming device needs to be changed so that those whose destination data is “124” are accepted. This requires much labor, time and cost.
Furthermore, when a design change or specification change such as improvement or modification of a component (hereinafter, referred to as “design change or the like”) is made after beginning to put the image forming device on the market, process cartridges in a plurality of versions are existent in the market. Depending on the contents of the design change or the like, a failure may occur if a printing operation is performed using a process cartridge in an older version without making any change. For example, due to a design change or the like, there is a case that addresses in the nonvolatile memory which are not used in the initial period after release are used (such unused addresses are usually provided in case for future function enhancement). This case also requires much labor, time and cost since a program of the main body of the image forming device is changed to respond to each design change or the like.